This study focused on the investigation microplastics (MPs) with a size of ≤1.0 mm in sand samples from Thanh Phu beach, Ben Tre, Vietnam. MPs in sand from the clam beach (from 39.67 ± 6.67 to 92.00 ± 12.93 items kg-1 dried sand) were higher than those from the bathing beach (from 21.33 ± 8.76 to 51.67 ± 16.11 items kg-1 dried sand), indicating a direct contribution of MPs from coastal aquaculture. For the clam beach, MPs in surface samples (0-4 cm) were lower than in deep samples (4-6 cm). In contrast, MPs in surface samples (0-2 cm) from the bathing beach were higher than deep samples (2-5 cm). A combination of microscopy and Fourier-transform infrared spectroscopy methods confirmed that 62.5% of the representative MPs samples or 18.9% of the suspected MPs samples were plastics. Low-density polyethylene, polypropylene and polyethylene terephthalate were the largest in abundance. Further studies are needed to assess the environmental risk of MPs accumulation.

Panax ginseng and Panax quinquefolium are two valuable Chinese herbal medicines that should not be mixed because they differ in drug properties and efficacy. The traditional identification method is easily affected by subjective factors and cannot effectively distinguish between ginseng products. This study aimed to develop a new chemical analysis method to visually identify P. ginseng and P. quinquefolium. In this method, a large number of sequences containing G-quadruplex were generated by loop-mediated isothermal amplification, and the combination of G-quadruplex and hemin was used to form deoxyribozyme, which catalyzed the color change of H2O2. Artificial simulation of adulteration experiments revealed that this method could detect more than 20% adulterated P. quinquefolium. Compared with the traditional identification methods, this technology was simpler and more efficient, providing a reference for developing rapid visual identification methods and reagents for P. ginseng and P. quinquefolium.

While noise is generally believed to impair performance, the detection of weak stimuli can sometimes be enhanced by introducing optimum noise levels. This phenomenon is termed \'Stochastic Resonance\' (SR). Past evidence suggests that autistic individuals exhibit higher neural noise than neurotypical individuals. It has been proposed that the enhanced performance in Autism Spectrum Disorder (ASD) on some tasks could be due to SR. Here we present a computational model, lab-based, and online visual identification experiments to find corroborating evidence for this hypothesis in individuals without a formal ASD diagnosis. Our modeling predicts that artificially increasing noise results in SR for individuals with low internal noise (e.g., neurotypical), however not for those with higher internal noise (e.g., autistic, or neurotypical individuals with higher autistic traits). It also predicts that at low stimulus noise, individuals with higher internal noise outperform those with lower internal noise. We tested these predictions using visual identification tasks among participants from the general population with autistic traits measured by the Autism-Spectrum Quotient (AQ). While all participants showed SR in the lab-based experiment, this did not support our model strongly. In the online experiment, significant SR was not found, however participants with higher AQ scores outperformed those with lower AQ scores at low stimulus noise levels, which is consistent with our modeling. In conclusion, our study is the first to investigate the link between SR and superior performance by those with ASD-related traits, and reports limited evidence to support the high neural noise/SR hypothesis.

Human exposure to microplastics (MPs) through drinking water has drawn serious concern recently because of the potential adverse health effects. Although there are reports on the occurrence of MPs in bottled water, little is known about the abundance of a whole spectrum of MPs with sizes ranging from 1 µm to 5 mm due to the restrictions of conventional MPs detection methods. Some studies using micro-Raman spectroscopy can achieve MPs with a size of <10 µm, however, quantitation of all MPs was extremely time consuming and only a small portion (<10%) of MPs would be analyzed. The present study quantified MPs from nine brands of bottled water using fluorescence microscopy and flow cytometry for MPs with a size of ≥50 µm and a size of <50 µm, respectively. The average abundance of MPs with a size of ≥50 µm in bottled water samples was found ranging from 8-50 particles L-1, while MPs with a size of <50 µm were found to be 1570-17,817 particles L-1, where the MPs abundance from mineral water samples were significantly more than distilled and spring water samples. The modal size and shape of MPs were found at 1 µm and fragments, respectively. Besides, three tap water samples obtained locally were analyzed and compared with the bottled water samples, where less MPs were found in tap water samples. In addition, contamination of MPs from bottle and cap and interference by addition of mineral salts were studied, where no significant difference from all these processes to the control sample was found, suggesting the major contamination of MPs was from other manufacturing processes. Estimated daily intake (EDI) of MPs increased substantially when data of small MPs are included, suggesting that previously reports on exposure of MPs from drinking water might be underestimated, as only large MPs were considered.

Two water-soluble single-benzene-based chromophores, 2,5-di(azetidine-1-yl)-tereph- thalic acid (DAPA) and its disodium carboxylate (DAP-Na), were conveniently obtained. Both chromophores preserved moderate quantum yields in a wide range of polar and protonic solvents. Spectroscopic studies demonstrated that DAPA exhibited red luminescence as well as large Stokes shift (>200 nm) in aqueous solutions. Femtosecond transient absorption spectra illustrated quadrupolar DAPA usually involved the formation of an intramolecular charge transfer state. Its Frank−Condon state could be rapidly relaxed to a slight symmetry-breaking state upon light excitation following the solvent relaxation, then the slight charge separation may occur and the charge localization became partially asymmetrical in polar environments. Density functional theory (DFT) calculation results were supported well with the experimental measurements. Unique pH-dependent fluorescent properties endows the two chromophores with rapid, highly selective, and sensitive responses to the amino acids in aqueous media. In detail, DAPA served as a fluorescence turn-on probe with a detection limit (DL) of 0.50 μM for Arg and with that of 0.41 μM for Lys. In contrast, DAP-Na featured bright green luminescence and showed fluorescence turn-off responses to Asp and Glu with the DLs of 0.12 μM and 0.16 μM, respectively. Meanwhile, these two simple-structure probes exhibited strong anti-interference ability towards other natural amino acids and realized visual identification of specific analytes. The present work helps to understand the photophysic−structure relationship of these kinds of compounds and render their fluorescent detection applications.

Whilst many identification methods have been widely described and discussed in the literature, and considered in disaster and humanitarian contexts, there has been limited reporting and evaluation of the identification methods used in domestic medico-legal death investigation contexts. The aim of this study was to evaluate the identification methods utilised at the Victorian Institute of Forensic Medicine (VIFM), which forms part of a coronial medico-legal death investigation system. The method of identification and time taken to complete the identification were reviewed for all cases admitted to the VIFM over a five-year period from 1 July 2015 to 30 June 2020. The majority, 91%, of individuals admitted to the VIFM were visually identified. The remaining 9% of cases required identification by primary methods (i.e. fingerprints, DNA or dental) or, when those methods were not possible, by secondary methods (i.e. circumstantial). Visual identifications were the timeliest, taking an average of 1.5 days, whilst primary identification methods required an average of 5 days to complete. The triaging of identification methods, dependent on the case context, body preservation, availability of ante-mortem data, legal requirements and admissibility of the method, are determined by identification coordinators within the Human Identification Service (HIS) to ensure the most appropriate and timely method is employed. This review of human identification methods provides the foundation for future analyses to compare workflow processes and improve identification methods utilised in domestic medico-legal contexts.

Estimates of marine debris are often based on beach surveys. Few studies have documented the veracity of these observations and the factors that may affect accuracy. Our laboratory-scale experiment identified potential sources of error associated with visual identification of marine debris (1-2 cm long) during shoreline surveys of sand beaches. Characteristics of the survey site (beach characteristics), observer (personal characteristics), and debris (color and size) may be important factors to consider when analyzing data from shoreline surveys. The results of this study show that the ability of individuals to accurately identify plastic fragments depends on the plastic and sand color, and density of shell fragments. Most suggestively, the high accuracy of blue plastic counts (95%) and the under-counting of white (50%) and clear plastic counts (55%) confirmed the hypothesis that a significant amount of clear and white plastic fragments may be missed during shoreline surveys. These results highlight the need for further research and possible modifications of visual shoreline survey methodologies in order to optimize this cost-effective method of marine debris monitoring.

Current effort merging rational design of colorimetric sensor array with portable and easy-to-use hand-held readers delivers an effective and convenient method for on-site detection and discrimination of explosives. However, on the one hand, there are rare relevant reports; on the other hand, some limitations regarding direct sensing, color retention, and array extendibility still remain. Herein, urea-functionalized poly(ionic liquid) photonic spheres were employed to construct a brand-new colorimetric sensor array for directly identifying five nitroaromatic explosives with a smartphone. It is found that the strong hydrogen bonding between the urea motifs and the nitro groups offers the spheres high affinity for binding the targets, whereas the existence of other abundant intermolecular interactions in poly(ionic liquid) units renders one single sphere eligible for prominent cross-responses to a broad range of analytes. Besides, in our case, opal-like photonic crystal structures other than chemical dyes are used to fabricate a new style of colorimetric array. Such structural colors can be vivid and unchanged over a long period even in hazard environments. Importantly, through simply altering the preparation conditions of our PIL spheres, a pool of sensing elements could be added to the developed array for discrimination of extended target systems such as more explosives and even their mixtures in real-world context.

Fluorescence microscopy is an important step in visual identification of microplastics and is used to highlight white and transparent plastics that are otherwise easily missed or misidentified. Investigators using fluorescence must proceed with caution, however, as fluorescence photobleaching can significantly reduce the fluorescence output of samples within experimentally relevant time frames. We report on the photobleaching rate and subsequent lack of fluorescence recovery of five common plastics. Our results reveal statistically different photobleaching rates across plastic types. In the best-case scenario of low illumination intensity and a robust plastic, initial fluorescence intensity decayed by 10% in just 11(3) s and by 33% in 230(40) s. In all cases, fluorescence failed to recover more than 13(8)% in 3 h. These results indicate that significant bleaching can occur while searching a sample for plastics to identify and that the lack of recovery can compromise samples for further study.

BACKGROUND: The present study aimed to establish a method for the detection and quantification of azodicarbonamide (ADC) in flour using hyperspectral imaging technology. Hyperspectral images of pure flour, pure ADC and flour-ADC mixtures with different concentrations of ADC were collected. F-values of one-way analysis of variance for all possible wavebands within the spectra of the flour and ADC were calculated, and the maximum value indicated that the two wavebands have more significant differences, i.e. the optimal two wavebands. Threshold segmentation was used for band ratio images of two wavebands to create a binary image. This allowed visual identification of ADC-rich pixels in the mixtures.
RESULTS: The two wavebands with the largest difference between flour and ADC were 2039 nm and 1892 nm. Using the binary image construction method, different concentrations of ADC in flour were identified. The minimum detected concentration was 0.2 g kg-1 . In the mixtures, the number of ADC-rich pixels detected had a good linear relationship with the ADC concentrations, with a correlation coefficient of 0.9845.
CONCLUSIONS: This study indicated that the band ratio algorithm combination with threshold segmentation for hyperspectral images provides a non-destructive method for detecting and quantifying of ADC in flour. © 2017 Society of Chemical Industry.